Consumption Of Primary Resources Research Articles

The future of thermoeconomics: From industrial cost minimization toward cumulative resources accounting and sustainability assessment

Thermoeconomics has been developed with the main object of first identifying, and then reducing the costs of the energy produced by industrial power plants. More recently, the same approach formalized in the Exergy Cost Theory has been recognized as a useful tool also in a wider field, like industrial symbiosis and sustainability assessment. To do this, exergy supply chains have been tracked backward and backward, to include in the primary resource consumption a more and more complete inventory of the indirect consumption.In the Authors’ opinion, the future of Thermoeconomics is to go on in this direction. If a very complete inventory of all indirect consumption were obtained, the sustainability assessment of a production process could be performed (at least in principle) by applying the idea that the lower its consumption (direct and indirect) of scarce primary resources, the more sustainable a production process is.In this paper, the idea of the Thermoeconomic Environment (TEE) is summarized, to highlight as it is a consistent ultimate boundary of the exergy cost accounting, where the origin of the exergy supply chains can be properly placed. Then, the frame of the TEE is used to discuss some possible options for obtaining a more complete inventory of all indirect consumption, and to outline its possible perspective connections with some relevant environmental models, coming from Biology, Dynamic of Populations, or Climatology.

Possibilities of reinforcement of subtle translucent concrete panel

Textile-reinforced concrete not only has many advantages that lead to less consumption of primary resources, but also enables the creation of thin and subtle elements. The high performance of such elements allows us to create interesting architectural features, such as translucent concrete. This article focusses on the possibility of reinforcing translucent concrete panels.

Consequences of omitting some important factors in the environmental analyses of commercial sodium silicate/sodium hydroxide use for alkaline activation in the light of comparison with cement-based composites

Alkali-activated materials (AAMs) based on various waste precursors were considered mostly as a sustainable alternative to Portland cement-based composites to date. However, a narrow focus on carbon dioxide savings in the environmental assessment of AAMs may not be sufficient to achieve a truly sustainable solution. Therefore, this paper provides a detailed insight into midpoint impact categories related to the production of AAMs based on waste precursors and conventional activators, as compared with common cement-based materials. The obtained results point to a higher environmental load of AAMs in several categories, such as ozone layer depletion, primary resource consumption, and terrestrial and aquatic ecotoxicity. In a hypothetical scenario, it is demonstrated that 10 % replacement of global concrete production by AAMs may result in notably increased emissions of ozone depletion substances (+35 %) and damage to the aquatic environment (+ 40 %). The risk for human health can then be higher. As for the aquatic environment, eutrophication can also lead to a significant increase in indirect emissions of CH4 and N2O having a high impact on the greenhouse effect. Hence, the importance of robust interdisciplinary research in the environmental assessment of AAMs should be emphasized, together with the need to use alternative alkaline substances, which would be more environment-friendly than conventional activators.

Visualising a framework for enhancing material circularity in building construction projects: Drivers, barriers, and strategies

Material circularity offers a novel perspective for industrial ecosystems, emphasising the reintegration of materials and products into the supply chain as valuable resources. This approach leads to a reduction in primary resource consumption and waste generation. Nevertheless, the incorporation of material circularity within the construction sector is hindered by barriers, necessitating careful analysis and practical solutions. Therefore, a clear roadmap with practical strategies that promote material circularity is needed. This study aims to identify the drivers, barriers, and strategies, concurrently formulating a framework to enhance material circularity in building construction projects. A sequential qualitative-quantitative mixed methods approach was employed to achieve this aim, which involved a literature review, 19 expert interviews, and two questionnaire surveys, which collectively yielded 230 responses. A literature review and expert interviews identified drivers, barriers, and strategies for implementing material circularity practices. Subsequently, using a five-point Likert scale, the first survey measured the importance of drivers and barriers. Then, the second survey was conducted to align strategies with corresponding barriers to enhance material circularity practices effectively. The results of the study indicated that cost savings primarily drive the adoption of material circularity. The most significant barrier was the underdeveloped marketplace for secondary products. The government plays a crucial role in addressing various barriers by implementing key strategies, including the introduction of regulations, policies, and economic incentives to promote material circularity. Finally, an evidence-based framework is proposed to assist practitioners and policymakers in creating a roadmap for implementing circular economy practices.

An efficient approach to utilize copper smelting slag: Separating nonferrous metals and reducing iron oxide at high temperature

Over 50 million tons of copper slag are produced worldwide annually. Stacking is currently the primary method used to treat copper slag, resulting in resource wastage and environmental issues. Using slag as a raw material in the steel industry is areasonablesolution. However, the presence of nonferrous metals degrades steel performance and corrodes smelting equipment, and the remaining slag poses environmental and sustainable challenges. Thus, this study focused on removal of nonferrous metals from copper slag and subsequent reduction of iron oxide. The experimental results showed that increasing the percentage of the chlorinating agent (calcium chloride), temperature, and duration, the removal percentage of copper initially increased linearly, then plateaued. The acidity coefficient had a marginal effect on copper removal percentage. The optimum chlorination roasting conditions were 13 % calcium chloride, 1373 K, and 0.5 h, resulting in removal percentages of 90.3 %, 81.9 %, and 82.7 % for copper, zinc, and lead, respectively. The appropriate oxygen partial pressure for chlorination roasting was 10-5–0.7 atm. The reduction percentage of iron oxide was approximately 82 % under roasting conditions of 1.5 h at 1373 K. Based on these results, a novel scheme for copper slag utilization is proposed that involves chlorination roasting for nonferrous metal removal, reduction roasting for iron oxide reduction, and melting to obtain molten iron and separate molten slag. The iron and slag are used for steel manufacturing and rock wool preparation, respectively. This scheme provides apromisingway to efficiently use copper slag, which will reduce primary resource consumption and pollution.

Curbside recycling increases household consumption

The environmental benefits of recycling depend on the extent to which it reduces virgin material consumption, yet there currently is a lack of empirical research on this relationship. This study addresses this gap by leveraging data on variation in the regional adoption of curbside recycling programs in North Carolina between 1999 and 2019. It uses difference-in-differences regression methods with two-way fixed effects to compare solid waste generation between similar communities with and without recycling programs. The study finds that during the study period solid waste generation in North Carolina increased by 6–10 % in the presence of curbside recycling, providing empirical evidence of circular economy rebound on the household level. This result suggests that the current focus of recycling programs and other circular economy activities, which is to increase the availability of secondary resources through collection and recycling, should be complemented by efforts to reduce the consumption of primary resources.

Belite cement clinker from autoclaved aerated concrete waste fines with high sulfate content

AbstractThe processing of belite cement clinker in a rotary kiln at about 1000°C in a CO2 atmosphere is a new recycling option for Autoclaved Aerated Concrete (AAC) waste that otherwise must be landfilled. Waste fine fractions from a sorting facility enriched in sulfate due to intermixing with waste plaster have been processed. During clinkering the cement clinker phase belite (Ca2SiO4) besides technical ellestadite, (Ca10(SiO4)3(SO4)3Cl2), or ternesite, (Ca5(SiO4)2SO4), are formed, depending on the addition of flux minerals. However, not all phases of the novel clinker react hydraulically. Whereas ternesite reacts with water, ellestadite forms complex solid solution series (Ca/Pb, SO4/PO4), which may be used as an insoluble reservoir mineral for undesirable constituents, such as phosphates and chlorides. The produced clinker has been successfully used to partially substitute OPC in AAC production in technical trials. Waste quantities and landfill costs are minimized, while at the same time, CO2 emissions and the primary resource consumption of AAC production are reduced. Joint work with industrial companies is underway to increase technology readiness. Particularly large reduction effects on CO2 emissions can be achieved through electrical heating of the rotary kiln.

Rebound effects following technological advancement? The case of a global shock in ferrochrome supply

Novel recycling technologies aim at increasing material efficiency by turning former waste products into valuable reclaimed resources. A key question is whether such technologies really reduce primary resource consumption or instead stimulate aggregated market demand. In this study the consequences of a positive shock in ferrochrome supply to the global stainless steel value chain is assessed quantitatively. This new source might be unlocked by technology under development for the recovery of chromium from carbon and stainless steel slags. The aim of this study is to quantitatively assess the income and substitution effects of reclaimed ferrochrome along a part of the stainless steel value chain. The impact of the supply shock is analysed by means of a vector autoregression (VAR), a dynamic model where lagged values of all included variables estimate current state of the system. Additionally, the VAR model is extended to a structural vector autoregression (SVAR) to account for contemporary effects as well. Both the VAR and SVAR model indicate that additional ferrochrome supply leads to an increase in aggregated supply of stainless steel, in combination with a substitution effect between ferrochrome and nickel. The extended SVAR model additionally highlights that contemporaneous effects do play an important role as well to capture the direct rebound effect in the ferrochrome market when working with quarterly data. In other words, an additional supply of reclaimed ferrochrome triggers a complex combination of interactions and consequences, yet it does not necessarily lead to a lower overall material consumption. The main contributions of this paper are the assessment of direct rebound effects of supplying reclaimed metals along the value chain and the demonstration that quantifying the effects of circular strategies is feasible.

A Novel Strategy for Remediation of Heavy Metal Removal and Oil/Water Separation from Carbon-Based Nanohybrid

Increasing the world population results in the consequent consumption of primary resources, which produces high amounts of waste. The increasing amount of waste has negatively impacted the environment and ecosystem. The growing population demands a high amount of food resources, which increases anthropogenic activities. So, Environmental pollution has become a severe problem due to this anthropogenic activity affecting our planet. This problem cannot be neglected and has become the most challenging task of the 21st century. Researchers are putting effort into developing new nanohybrid, which should be environmentally friendly, with greener methods of synthesis to overcome and remediate the environment from pollutants. Scientists are trying to move towards nanotechnologies and nanomaterials to resolve the upcoming challenges related to environmental pollutants. This article describes heavy metal pollutants, recovery of oil from wastewater, etc. This article will also focus on the carbon-based nanohybrid, which can be used for the environmental recovery strategies of polluted areas. In particular, this article will give more attention towards the recent method developed and method to capturing heavy metal using silver fabricated reduced graphene oxide nanohybrid for the application of heavy metal capture and separation of oil water.

Изучение барьеров на пути к экономике замкнутого цикла (малые и средние предприятия)

Relevance. The pursuit of sustainable development against the backdrop of increasing demands for resources in an environment of scarcity, as well as growing social and environmental problems, reflect the importance of finding solutions to maintain economic growth, with due attention to the solution of the forenamed social and environmental problems, while reducing the demand for primary resources. A circular economy model that focuses on minimizing waste and consumption of primary resources, extending the useful life of products, provides solutions to these problems and contributes to the achievement of sustainable development goals. In practice, this model is not widely used, due, between other reasons, to barriers preventing the transition from a linear model of the economy to a circular one. And although regions, industries and enterprises may face various barriers in the implementation of circular solutions, it is possible to identify potential barriers that are typical for most. The purpose of the work is to identify and classify the barriers to the transition to a circular economy (with an emphasis on small and medium-sized enterprises), which can serve as the basis for the subsequent development of a roadmap for the transition to a circular economy and overcoming such. Target groups. The results of the study can resonate with academia, policy makers and business leaders to achieve a systemic, inclusive and competitive circular economy; serve as a basis for developing a roadmap for the transition to a circular economy at different levels, developing ways to overcome barriers that impede this transition. Materials and methods. The study is based on data obtained from the analysis of publications of Russian and foreign scholars on this topic. To achieve the stated goal, general scientific methods of cognition used in economic science, in particular, methods of comparative and logical analysis, were used. Results. The main features of the circular economy are considered; describes the main points related to the development of a methodology for introducing a circular economy at the enterprise level; analyzed and classified the barriers faced by enterprises in the transition to a circular economy model; the importance of a structural and systematic approach was emphasized for the effective transition from a linear model of the economy to a circular economy with the involvement of stakeholders and consumers. Conclusions. The circular economy model provides opportunities for sustainable economic growth, reduces waste and the use of primary resources, provides consumers with innovative and durable products, and contributes to solving social and environmental problems. At the same time, existing barriers (financial, institutional, legislative, infrastructural, environmental, cultural, supply chain issues and low levels of cooperation) make it difficult to move towards a circular economy. It seems important to study such barriers in order to develop ways to overcome them and transform them into potential drivers of planned changes.

Belite cement clinker from autoclaved aerated concrete waste – A contribution towards CO2‐reduced circular building materials

AbstractThe processing of belite cement clinker in a rotary kiln at about 1000oC is a new recycling option for autoclaved aerated concrete (AAC) waste that otherwise must be landfilled. The clinker produced can partially substitute ordinary portland cement (OPC) in AAC production. Waste quantities and landfill costs are minimized, while at the same time CO2 emissions and the primary resource consumption of AAC production are reduced. The technology is currently under development. New analytical possibilities and modeling have made it possible to optimize the process conditions to such an extent that the use of belite cement clinker in aerated concrete production has already been technically tested. Particularly large effects on CO2 emissions can be achieved through the electrical heating of the rotary kiln and the coupled sequestration of the released CO2 in other secondary products such as recycled aggregate for concrete production from waste concrete. Comparable concepts for the AAC cycle are currently being worked on together with the industry partner Xella. Although decentralized plant concepts would be useful in order to minimize transportation, small plants are currently not economical according to initial estimates. In the long term, emission‐free product cycles are aimed at.

Investigation of the optimal price for recycled aggregate concrete — an experimental approach

The use of recycled aggregate concrete can reduce the use of primary resources as well as the amount of waste generated. However, the diffusion of recycled aggregate concrete requires the price competitiveness. This study investigated the question of what the optimal price for recycled aggregate concrete should be in order to be generally accepted and what monetary measures can be taken to increase the willingness to use recycled aggregate concrete. The questions have been examined by applying a randomised controlled factorial design as well as the Price Sensitivity Meter. It has been found that the optimal price corridor for recycled aggregate concrete should lie between 83.3% and 100% of the regional reference price for conventional concrete. In addition, it was found that the reimbursement of additional costs necessary for ensuring the optimal price for recycled aggregate concrete, significantly increases the willingness to use it. The present results suggest that a possible temporary state aid to ensure price competitiveness could increase the use of recycled aggregate concrete and thus reduce the amount of waste generated and primary resource consumption. For the design of a possible monetary aid for the use of recycled aggregate concrete, a simple algorithm has been proposed that minimises possible misincentives and takes into account the proportion of recycled aggregate actually used in concrete relative to the maximum permissible proportion.

Functional Nanohybrids and Nanocomposites Development for the Removal of Environmental Pollutants and Bioremediation.

World population growth, with the consequent consumption of primary resources and production of waste, is progressively and seriously increasing the impact of anthropic activities on the environment and ecosystems. Environmental pollution deriving from anthropogenic activities is nowadays a serious problem that afflicts our planet and that cannot be neglected. In this regard, one of the most challenging tasks of the 21st century is to develop new eco-friendly, sustainable and economically-sound technologies to remediate the environment from pollutants. Nanotechnologies and new performing nanomaterials, thanks to their unique features, such as high surface area (surface/volume ratio), catalytic capacity, reactivity and easy functionalization to chemically modulate their properties, represent potential for the development of sustainable, advanced and innovative products/techniques for environmental (bio)remediation. This review discusses the most recent innovations of environmental recovery strategies of polluted areas based on different nanocomposites and nanohybrids with some examples of their use in combination with bioremediation techniques. In particular, attention is focused on eco-friendly and regenerable nano-solutions and their safe-by-design properties to support the latest research and innovation on sustainable strategies in the field of environmental (bio)remediation.

INVESTIGATION OF MODES JOINT OPERATION OF HEAT UTILIZERS AND BOILER UNITS

Given the share of energy consumption by powerful industrial enterprises in the overall balance of world consumption, it can be shown that at this stage of technology development, primary energy is not used efficiently enough, turning more into unused heat. Increasing the use of secondary energy resources reduces the consumption of primary resources, the cost of which is constantly growing, and solves the problem of improving the environmental situation in the locations of large enterprises. Thermal secondary energy losses are reduced by installing tail heating surfaces, such as economizers and air heaters.
 The operation of the boiler unit is characterized by changes in its basic parameters over time, largely depending on the degree of load on the boiler. The degree of loading of the economizer affects the efficiency of its work. Determining the parameters of joint operation of heat recovery units and the boiler unit with changes in heat capacity will determine the most rational modes of operation of the system in terms of fuel economy.
 The aim of the study is to determine the characteristic indicators of joint operation of the boiler unit at different degrees of its load, with heat recovery units installed in the required amount to determine the most efficient modes of operation of the system.
 Economizers have the lowest thermal efficiency at a load of about 40% of the boiler power, and the highest at rated load. The results of calculations of the joint operation of the boiler unit with heat recovery units show significant changes in the possible cooling temperature of the combustion products behind the boiler when the boiler load changes. Using the above technique, it is possible to determine such a combination of the number of utilizers and different distribution of combustion products between them, at which the optimal gas temperature can be achieved for each specific mode of operation of the installation.

The Structural Use of Recycled Aggregate Concrete for Renovation of Massive External Walls of Czech Fortification

The use of recycled aggregate concrete is mainly negatively affected by its poorer mechanical and long-term properties. However, there are few structural applications for which recycled aggregates can be used. In this case study, the possibility of use as massive external reinforcement wall is verified. For this structural application, the most important characteristics are freeze–thaw resistance, and carbonation resistance and then the mechanical properties such as compressive strength. Durability characteristics of the materials have been tested and improved in the study. The mechanical properties and durability of recycled aggregated concrete have been verified and crystalline mixture has been used to improve durability. The specific structural application of the massive external reinforcement wall is for the renovation of the Czech WW2 concrete fortification, which is one of the most important cultural heritages of the Czech Republic of the 20th century. However, these buildings have not yet been professionally rebuilt, but this research project aims to change this trend. The thickness of the bunker wall is between 0.5 and 3.5 m (depending on the type of bunker) which leads to a huge amount of concrete and primary resources consumption; however, the security function is not necessary today, so the reconstruction could be provided by recycled aggregate concrete. The results showed a positive effect of the crystalline mixture on the essential properties of recycled aggregate concrete. Recycled aggregate concrete with a complete replacement of aggregate by recycled concrete or masonry aggregate is possible to use for the reconstruction of the Czech WW2 concrete fortification and save natural aggregate as a primary resource.

Environmental perspectives of fine grounded concrete powder: LCA case study of light-weight concrete block

The construction elements produced with low demand for primary resources are being developed in the building industry. However, not only consumption of primary resources but also environmental impacts of such products should be considered to increase the sustainability of the construction industry. To investigate the environmental impacts of lightweight concrete blocks, life cycle assessment (LCA) was used as an analytical tool according to the EN 15 804 + A2. Firstly, the properties of fine grounded concrete powder (FRWC) were measured to declare functionality and potential to use of the considered product. Then, the lightweight concrete block containing FRWC was designed. The potential environmental impacts of the lightweight concrete block were assessed for the following phases: raw material production, transport of materials, production of concrete block, and end of life of the block. The considered system boundaries includes the production of fine grounded concrete powder, which was produced by recycling demolished concrete structures. The results were related to 1 tun of lightweight concrete block. Unsurprisingly, the calculated impact is mainly influenced by cement production. The total impact of the life cycle of 1 t of the lightweight block is 336 kg CO2 eq. On the other hand, the lightweight block reached better results in the comparison with the Aerated Autoclaved Concrete block in most of the categories.

The Thermoeconomic Environment Cost Indicator (iex-TEE) as a One-Dimensional Measure of Resource Sustainability

This paper presents a conceptual development of sustainability evaluation, through an exergy-based indicator, by using the new concept of the Thermoeconomic Environment (TEE). The exergy-based accounting methods here considered as a background are Extended Exergy Accounting (EEA), which can be used to quantify the exergy cost of externalities like labor, monetary inputs, and pollutants, and Cumulative Exergy Consumption (CExC), which can be used to quantify the consumption of primary resources embodied in a final product or service. The new concept of bioresource stock replacement cost is presented, highlighting how the framework of the TEE offers an option for evaluating the exergy cost of products of biological systems. This sustainability indicator is defined based on the exergy cost of all resources directly and indirectly consumed by the system, the equivalent exergy cost of all externalities implied in the production process and the exergy cost of the final product.

Resource Pressure of Carpets: Guiding Their Circular Design

When designing a product, many decisions are made that determine the environmental impacts that the product will eventually exert on our planet. Therefore, it is paramount to have considered the environmental performance already in the design phase. In this contribution, we showcase the application of the recently developed resource pressure (RP) method to assess the environmental sustainability of various carpet design alternatives. This method consists of qualitative guidelines and a quantitative indicator. With the Earth’s carrying capacity as a reference, the product system is evaluated in relation to its consumption of primary resources and the final generation of waste. Several scenarios are developed by following the design guidelines provided by this method. Those scenarios aim at identifying the most promising circular strategies for reducing the products’ resource pressure. To assess the validity of the RP method, the results are compared to a simplified LCA study. This comparison showed a close correlation for most of the considered impact categories. It confirms that the RP method can effectively predict environmental impacts across a wide range of impact categories, reducing the amount of necessary data and simplifying the calculations. It can therefore support designers in considering the environmental effects easily, from the beginning of the design process onward. Moreover, the simplicity of this method makes it attractive for application by practitioners who are not themselves experts in environmental assessments.

A Thermodynamic Measure of Sustainability

A novel thermodynamic approach to the quantification of the “degree of sustainability” is proposed and discussed. The method includes a rigorous -and innovative- conversion procedure of the so-called externalities that leads to their expression in terms of the exergy of their equivalent primary resources consumption. Such a thermodynamic approach suggests a detailed re-evaluation of the concept of sustainability because it is well-known that the Second Law strictly negates the possibility for any open and evolving system to maintain itself in a “sustainable” state without availing itself of a continuous supply of low-entropy (i.e., high specific exergy) input. If a human society is modeled as an open system, its capacity to “grow sustainably” depends not only on how it uses non-renewable resources, but also on the rate at which it exploits the renewable ones. The necessary inclusion of different forms of energy- and material flows in such an analysis constitutes per se an argument in favor of a resource-based exergy metrics. While it is true that the thermodynamically oriented approach proposed here neglects all of the non-thermodynamic attributes of a “sustainable system” (in the Bruntland sense), it is also clear that it constitutes a rigorous basis on which different physically possible scenarios can be rigorously evaluated. Non-thermodynamic indicators can be still used at a “second level analysis” and maintain their usefulness to indicate which one of the “thermodynamically least unsustainable” scenarios is most convenient from an ethical or socio-economic perspective for the considered community or for the society as a whole. The proposed indicator is known as “Exergy Footprint,” and the advantages of its systematic application to the identification of “sustainable growth paths” is discussed in the Conclusions.

The conceptualization of societal impacts of landfill mining – A system dynamics approach

Landfill mining (LFM) refers to the excavation and processing of formerly buried waste streams. It offers significant environmental and societal benefits through the mitigation of greenhouse gas emissions or the reduction of long-term waste management costs. LFM’s profitability, however, is still in question and public investment support might be necessary to fully exploit its potential. To enable decision-makers to identify the best solutions for a landfill site, societal impacts of LFM still have to be investigated. Throughout relevant literature, societal impacts of LFM projects have only selectively been studied and it remains unclear if and which benefits justify policy interventions. This paper firstly provides a comprehensive conceptualization of the societal impact of an LFM project and dives into the underlying societal context of this emerging industry. It disentangles formerly identified burdens and benefits by applying a system dynamics approach to LFM research. Based on this approach, four causal loop diagrams are presented showing how LFM is embedded into its societal context, analyzing the composition of the net societal impact of an LFM project, the mechanisms influencing LFM’s public acceptance, and the dynamics of the market acceptance of LFM products. Key variables and leverage points have been identified, such as (i) technology choices influencing avoided impacts from the mitigations of primary resource consumption, since many societal impacts are closely related to environmental impacts, (ii) a timely and broad stakeholder involvement to prevent project opposition, and (iii) the after-use of the mined landfill, generating a major part of the local and regional societal benefits but also creating potential conflicts between stakeholder interests. Key intradimensional trade-offs and potential conflicts were identified in (i) spatial and (ii) temporal risk distribution, (iii) conflicting societal goals of the after-use such as job creations and recreation, as well as (iv) material and energy recuperation. These findings provide important insights for LFM decision-makers and can help to implement this emerging industry in a sustainable way.